126 PROCEEDINGS OP THE MALACOLOGICAL SOCIETY. 



pellucida with the whole free lip edged with a periostacal membrane. 

 While, then, the flattening of the columellar lip is a definite character 

 in species such as j)y>'enaica, in which it is highly developed, I doubt 

 whether its presence to a degree which is just plainly perceptible 

 and which fades of! into filmy extensions of uncalcified periostracum 

 is of much moment. Apart from the lip, the new shell does not 

 obviously differ from specimens of major in the British Museum, 

 except that these are, with one exception, a good deal larger ; it is 

 indistinguishable from Mr. Taylor's French specimen identified as 

 major, which is the same size. Moquin-Tandon's figure of the radula 

 is too indefinite to be of any help. A genital anatomy which is 

 apparently substantially the same as that of the Cusop snail is 

 figured by A. Schmidt ^ for drajmrnaldi from Bonn, which is 

 generally held to be isynonymous with major, and by C. Pollonera ^ 

 for stahilei from Italy, the latter remarking on the affinity of this 

 species to major, which does not occur in Italy ; he figures both 

 stahilei and major with a small flattening of the columellar lip. 

 Mr. P. Hesse, who is engaged on a monograph of the palsearctic 

 Vitrinidaa, has been good enough to allow me to see drawings of the 

 genitalia of major from the Rhine valley ; they correspond very 

 well with the Cusop form. 



The anatomy of many species being unknown to me, it is hardly 

 possible to reach a certain diagnosis. Judging from the shell alone, 

 the new form might be reitteri (Bosnia), angelicce (Greenland), or 

 penchinati ^ (Pyrenees), as these are represented in the British 

 Museum. By the same criterion it seems certain that it is not 

 elongata, brevis, diapJiana, nivalis, alpina, glacialis, villce, or annidaris. 

 On anatomical grounds it is plainly different from diaphana, 

 hrevis, and elongata (Eckardt),^ and from the Italian gceotiformis 

 and pegorarii (Pollonera).^ On one ground and another, therefore, 

 of the six species described by Moquin-Tandon it can only be major, 

 of the eleven dealt with by Pollonera only major or stahilei (which 

 may not be really different from major), of Germain's^ ten species 

 (with five other described forms sunk as synonyms) only major, 

 of Geyer's * seven species only major. This very dangerous method 

 of exclusion brings us to the same conclusion as does such positive 

 evidence as is available, and there appear to be fairly satisfactory 

 grounds for a provisional conclusion that the Cusop species is 

 Vitrina major. It is just possible that it is a new species altogether : 

 this can only be settled by an intimate comparison with authentic 



^ " Geschlectsapp. d. Stylomm." : Abhandl. Naturw. Ver. f. Sachsen <& 

 Thuring., HaUe, i, No. 1, 1855, p. 49, and fig. 106. 



2 Atti R. Accad. Sci. Torino, xix, 1884, p. 412, pi. x, fig. 46. 



^ Germain (Mollusques de la France, ii, 1913, p. 62) says penchinati = 

 pyrenaica. 



* Loc. cit. 



* Land- und Susswasser-MoUusken, 1909, pp. 18 &. 



